Are you sure? It's just a game manual and it's only part of one sentence of a very brief history of the train -- "Famous cars included the Imperial varnish of the Russian Tsar, whose dark blue cars proudly bore the resplendent Double Eagle;...."(it then lists of Viceroy of India). I'm 100% certain they wouldn't just make something like that up, and I also know that some of the other famous passengers they list check out, but it just doesn't seem to fit. I saw a little book on the OE in a library once, read through the section on distinguished passengers, and saw no mention, although he obviously wouldn't have travelled as a regular passenger - not sure if that would matter.
To answer your question, I'd check E-bay for the game (you might like it, whatever your opinion on computer games; it's completely unique) - I actually checked a few days ago because I'm afraid my copy may've been lost. It was going for under $10 at the time. Just make sure it comes w/ the manual, of course. It also might be archived online or elsewhere for free access, for all I know, but I'm warning you it ain't much.
I _had_ an extra copy (I bought a second copy of the game from e-bay just for an included gameguide), but now I seem to be reduced to one manual + the gameguide.
(actually, now that I've said all that, I could just type out the relevant pages (about 3 paragraphs total), do you want me to do that? It wouldn't be a problem but it's mostly on the OE and not about the Tsar, so I'm not sure if you're interested. You'd only miss out on the diagrams if so.)